Abstract:
Clay as abundant natural products can be used for various things, one of which is a
coagulant in water treatment. This research has been utilized Cengar clay as a liquid
coagulant source. The liquid coagulant was made through extraction of the Cengar clay
by using sulfuric acid solution with variation of concentration, temperature and
extraction time. After measuring by Atomic Absorption Spectrophotometry methode,
two liquid coagulants with the highest content of Al and Fe ions (mg/L) was found.
There are (mg/L) : Al 28.118 and Fe 26.818 for liquid coagulant of Al>Fe type and Al
23.926 and Fe 34.993 for liquid coagulant of Al<Fe type, respectively. The two
coagulants were applied onto peat water for removing Mn (II) and Mg (II) ions. The
content of Mn (II) and Mg (II) in the peat water are 28.714 mg/L and 20.200 mg/L,
respectively. Under coagulation treatment by the liquid coagulant of Al>Fe, the content
of Mn (II) and Mg (II) in the peat water was reduced to 24.429 mg/L and 17.2 mg/L,
similar to the liquid coagulant of Al<Fe where the content of Mn (II) and Mg (II) was
also reduced to11.524 mg/L and 8.167 mg/L. The data were shown that the liquid
coagulant of Al<Fe was more effective for reducing the content of Mn (II) ion as high
as 59.9% and Mg (II) 14.9%. However, the content of Mn (II) ion in the peat water after treatment is not fulfilling the PERMENKES No.416/MENKES/PER/IX/ 1990 about the requirements list of clean water quality
